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x86/boot: Fix another __read_cr4() case on 486
[deliverable/linux.git] / drivers / rtc / rtc-ds1307.c
1 /*
2 * rtc-ds1307.c - RTC driver for some mostly-compatible I2C chips.
3 *
4 * Copyright (C) 2005 James Chapman (ds1337 core)
5 * Copyright (C) 2006 David Brownell
6 * Copyright (C) 2009 Matthias Fuchs (rx8025 support)
7 * Copyright (C) 2012 Bertrand Achard (nvram access fixes)
8 *
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License version 2 as
11 * published by the Free Software Foundation.
12 */
13
14 #include <linux/bcd.h>
15 #include <linux/i2c.h>
16 #include <linux/init.h>
17 #include <linux/module.h>
18 #include <linux/rtc/ds1307.h>
19 #include <linux/rtc.h>
20 #include <linux/slab.h>
21 #include <linux/string.h>
22 #include <linux/hwmon.h>
23 #include <linux/hwmon-sysfs.h>
24 #include <linux/clk-provider.h>
25
26 /*
27 * We can't determine type by probing, but if we expect pre-Linux code
28 * to have set the chip up as a clock (turning on the oscillator and
29 * setting the date and time), Linux can ignore the non-clock features.
30 * That's a natural job for a factory or repair bench.
31 */
32 enum ds_type {
33 ds_1307,
34 ds_1337,
35 ds_1338,
36 ds_1339,
37 ds_1340,
38 ds_1388,
39 ds_3231,
40 m41t00,
41 mcp794xx,
42 rx_8025,
43 last_ds_type /* always last */
44 /* rs5c372 too? different address... */
45 };
46
47
48 /* RTC registers don't differ much, except for the century flag */
49 #define DS1307_REG_SECS 0x00 /* 00-59 */
50 # define DS1307_BIT_CH 0x80
51 # define DS1340_BIT_nEOSC 0x80
52 # define MCP794XX_BIT_ST 0x80
53 #define DS1307_REG_MIN 0x01 /* 00-59 */
54 #define DS1307_REG_HOUR 0x02 /* 00-23, or 1-12{am,pm} */
55 # define DS1307_BIT_12HR 0x40 /* in REG_HOUR */
56 # define DS1307_BIT_PM 0x20 /* in REG_HOUR */
57 # define DS1340_BIT_CENTURY_EN 0x80 /* in REG_HOUR */
58 # define DS1340_BIT_CENTURY 0x40 /* in REG_HOUR */
59 #define DS1307_REG_WDAY 0x03 /* 01-07 */
60 # define MCP794XX_BIT_VBATEN 0x08
61 #define DS1307_REG_MDAY 0x04 /* 01-31 */
62 #define DS1307_REG_MONTH 0x05 /* 01-12 */
63 # define DS1337_BIT_CENTURY 0x80 /* in REG_MONTH */
64 #define DS1307_REG_YEAR 0x06 /* 00-99 */
65
66 /*
67 * Other registers (control, status, alarms, trickle charge, NVRAM, etc)
68 * start at 7, and they differ a LOT. Only control and status matter for
69 * basic RTC date and time functionality; be careful using them.
70 */
71 #define DS1307_REG_CONTROL 0x07 /* or ds1338 */
72 # define DS1307_BIT_OUT 0x80
73 # define DS1338_BIT_OSF 0x20
74 # define DS1307_BIT_SQWE 0x10
75 # define DS1307_BIT_RS1 0x02
76 # define DS1307_BIT_RS0 0x01
77 #define DS1337_REG_CONTROL 0x0e
78 # define DS1337_BIT_nEOSC 0x80
79 # define DS1339_BIT_BBSQI 0x20
80 # define DS3231_BIT_BBSQW 0x40 /* same as BBSQI */
81 # define DS1337_BIT_RS2 0x10
82 # define DS1337_BIT_RS1 0x08
83 # define DS1337_BIT_INTCN 0x04
84 # define DS1337_BIT_A2IE 0x02
85 # define DS1337_BIT_A1IE 0x01
86 #define DS1340_REG_CONTROL 0x07
87 # define DS1340_BIT_OUT 0x80
88 # define DS1340_BIT_FT 0x40
89 # define DS1340_BIT_CALIB_SIGN 0x20
90 # define DS1340_M_CALIBRATION 0x1f
91 #define DS1340_REG_FLAG 0x09
92 # define DS1340_BIT_OSF 0x80
93 #define DS1337_REG_STATUS 0x0f
94 # define DS1337_BIT_OSF 0x80
95 # define DS3231_BIT_EN32KHZ 0x08
96 # define DS1337_BIT_A2I 0x02
97 # define DS1337_BIT_A1I 0x01
98 #define DS1339_REG_ALARM1_SECS 0x07
99
100 #define DS13XX_TRICKLE_CHARGER_MAGIC 0xa0
101
102 #define RX8025_REG_CTRL1 0x0e
103 # define RX8025_BIT_2412 0x20
104 #define RX8025_REG_CTRL2 0x0f
105 # define RX8025_BIT_PON 0x10
106 # define RX8025_BIT_VDET 0x40
107 # define RX8025_BIT_XST 0x20
108
109
110 struct ds1307 {
111 u8 offset; /* register's offset */
112 u8 regs[11];
113 u16 nvram_offset;
114 struct bin_attribute *nvram;
115 enum ds_type type;
116 unsigned long flags;
117 #define HAS_NVRAM 0 /* bit 0 == sysfs file active */
118 #define HAS_ALARM 1 /* bit 1 == irq claimed */
119 struct i2c_client *client;
120 struct rtc_device *rtc;
121 s32 (*read_block_data)(const struct i2c_client *client, u8 command,
122 u8 length, u8 *values);
123 s32 (*write_block_data)(const struct i2c_client *client, u8 command,
124 u8 length, const u8 *values);
125 #ifdef CONFIG_COMMON_CLK
126 struct clk_hw clks[2];
127 #endif
128 };
129
130 struct chip_desc {
131 unsigned alarm:1;
132 u16 nvram_offset;
133 u16 nvram_size;
134 u16 trickle_charger_reg;
135 u8 trickle_charger_setup;
136 u8 (*do_trickle_setup)(struct i2c_client *, uint32_t, bool);
137 };
138
139 static u8 do_trickle_setup_ds1339(struct i2c_client *,
140 uint32_t ohms, bool diode);
141
142 static struct chip_desc chips[last_ds_type] = {
143 [ds_1307] = {
144 .nvram_offset = 8,
145 .nvram_size = 56,
146 },
147 [ds_1337] = {
148 .alarm = 1,
149 },
150 [ds_1338] = {
151 .nvram_offset = 8,
152 .nvram_size = 56,
153 },
154 [ds_1339] = {
155 .alarm = 1,
156 .trickle_charger_reg = 0x10,
157 .do_trickle_setup = &do_trickle_setup_ds1339,
158 },
159 [ds_1340] = {
160 .trickle_charger_reg = 0x08,
161 },
162 [ds_1388] = {
163 .trickle_charger_reg = 0x0a,
164 },
165 [ds_3231] = {
166 .alarm = 1,
167 },
168 [mcp794xx] = {
169 .alarm = 1,
170 /* this is battery backed SRAM */
171 .nvram_offset = 0x20,
172 .nvram_size = 0x40,
173 },
174 };
175
176 static const struct i2c_device_id ds1307_id[] = {
177 { "ds1307", ds_1307 },
178 { "ds1337", ds_1337 },
179 { "ds1338", ds_1338 },
180 { "ds1339", ds_1339 },
181 { "ds1388", ds_1388 },
182 { "ds1340", ds_1340 },
183 { "ds3231", ds_3231 },
184 { "m41t00", m41t00 },
185 { "mcp7940x", mcp794xx },
186 { "mcp7941x", mcp794xx },
187 { "pt7c4338", ds_1307 },
188 { "rx8025", rx_8025 },
189 { }
190 };
191 MODULE_DEVICE_TABLE(i2c, ds1307_id);
192
193 /*----------------------------------------------------------------------*/
194
195 #define BLOCK_DATA_MAX_TRIES 10
196
197 static s32 ds1307_read_block_data_once(const struct i2c_client *client,
198 u8 command, u8 length, u8 *values)
199 {
200 s32 i, data;
201
202 for (i = 0; i < length; i++) {
203 data = i2c_smbus_read_byte_data(client, command + i);
204 if (data < 0)
205 return data;
206 values[i] = data;
207 }
208 return i;
209 }
210
211 static s32 ds1307_read_block_data(const struct i2c_client *client, u8 command,
212 u8 length, u8 *values)
213 {
214 u8 oldvalues[255];
215 s32 ret;
216 int tries = 0;
217
218 dev_dbg(&client->dev, "ds1307_read_block_data (length=%d)\n", length);
219 ret = ds1307_read_block_data_once(client, command, length, values);
220 if (ret < 0)
221 return ret;
222 do {
223 if (++tries > BLOCK_DATA_MAX_TRIES) {
224 dev_err(&client->dev,
225 "ds1307_read_block_data failed\n");
226 return -EIO;
227 }
228 memcpy(oldvalues, values, length);
229 ret = ds1307_read_block_data_once(client, command, length,
230 values);
231 if (ret < 0)
232 return ret;
233 } while (memcmp(oldvalues, values, length));
234 return length;
235 }
236
237 static s32 ds1307_write_block_data(const struct i2c_client *client, u8 command,
238 u8 length, const u8 *values)
239 {
240 u8 currvalues[255];
241 int tries = 0;
242
243 dev_dbg(&client->dev, "ds1307_write_block_data (length=%d)\n", length);
244 do {
245 s32 i, ret;
246
247 if (++tries > BLOCK_DATA_MAX_TRIES) {
248 dev_err(&client->dev,
249 "ds1307_write_block_data failed\n");
250 return -EIO;
251 }
252 for (i = 0; i < length; i++) {
253 ret = i2c_smbus_write_byte_data(client, command + i,
254 values[i]);
255 if (ret < 0)
256 return ret;
257 }
258 ret = ds1307_read_block_data_once(client, command, length,
259 currvalues);
260 if (ret < 0)
261 return ret;
262 } while (memcmp(currvalues, values, length));
263 return length;
264 }
265
266 /*----------------------------------------------------------------------*/
267
268 /* These RTC devices are not designed to be connected to a SMbus adapter.
269 SMbus limits block operations length to 32 bytes, whereas it's not
270 limited on I2C buses. As a result, accesses may exceed 32 bytes;
271 in that case, split them into smaller blocks */
272
273 static s32 ds1307_native_smbus_write_block_data(const struct i2c_client *client,
274 u8 command, u8 length, const u8 *values)
275 {
276 u8 suboffset = 0;
277
278 if (length <= I2C_SMBUS_BLOCK_MAX) {
279 s32 retval = i2c_smbus_write_i2c_block_data(client,
280 command, length, values);
281 if (retval < 0)
282 return retval;
283 return length;
284 }
285
286 while (suboffset < length) {
287 s32 retval = i2c_smbus_write_i2c_block_data(client,
288 command + suboffset,
289 min(I2C_SMBUS_BLOCK_MAX, length - suboffset),
290 values + suboffset);
291 if (retval < 0)
292 return retval;
293
294 suboffset += I2C_SMBUS_BLOCK_MAX;
295 }
296 return length;
297 }
298
299 static s32 ds1307_native_smbus_read_block_data(const struct i2c_client *client,
300 u8 command, u8 length, u8 *values)
301 {
302 u8 suboffset = 0;
303
304 if (length <= I2C_SMBUS_BLOCK_MAX)
305 return i2c_smbus_read_i2c_block_data(client,
306 command, length, values);
307
308 while (suboffset < length) {
309 s32 retval = i2c_smbus_read_i2c_block_data(client,
310 command + suboffset,
311 min(I2C_SMBUS_BLOCK_MAX, length - suboffset),
312 values + suboffset);
313 if (retval < 0)
314 return retval;
315
316 suboffset += I2C_SMBUS_BLOCK_MAX;
317 }
318 return length;
319 }
320
321 /*----------------------------------------------------------------------*/
322
323 /*
324 * The ds1337 and ds1339 both have two alarms, but we only use the first
325 * one (with a "seconds" field). For ds1337 we expect nINTA is our alarm
326 * signal; ds1339 chips have only one alarm signal.
327 */
328 static irqreturn_t ds1307_irq(int irq, void *dev_id)
329 {
330 struct i2c_client *client = dev_id;
331 struct ds1307 *ds1307 = i2c_get_clientdata(client);
332 struct mutex *lock = &ds1307->rtc->ops_lock;
333 int stat, control;
334
335 mutex_lock(lock);
336 stat = i2c_smbus_read_byte_data(client, DS1337_REG_STATUS);
337 if (stat < 0)
338 goto out;
339
340 if (stat & DS1337_BIT_A1I) {
341 stat &= ~DS1337_BIT_A1I;
342 i2c_smbus_write_byte_data(client, DS1337_REG_STATUS, stat);
343
344 control = i2c_smbus_read_byte_data(client, DS1337_REG_CONTROL);
345 if (control < 0)
346 goto out;
347
348 control &= ~DS1337_BIT_A1IE;
349 i2c_smbus_write_byte_data(client, DS1337_REG_CONTROL, control);
350
351 rtc_update_irq(ds1307->rtc, 1, RTC_AF | RTC_IRQF);
352 }
353
354 out:
355 mutex_unlock(lock);
356
357 return IRQ_HANDLED;
358 }
359
360 /*----------------------------------------------------------------------*/
361
362 static int ds1307_get_time(struct device *dev, struct rtc_time *t)
363 {
364 struct ds1307 *ds1307 = dev_get_drvdata(dev);
365 int tmp;
366
367 /* read the RTC date and time registers all at once */
368 tmp = ds1307->read_block_data(ds1307->client,
369 ds1307->offset, 7, ds1307->regs);
370 if (tmp != 7) {
371 dev_err(dev, "%s error %d\n", "read", tmp);
372 return -EIO;
373 }
374
375 dev_dbg(dev, "%s: %7ph\n", "read", ds1307->regs);
376
377 t->tm_sec = bcd2bin(ds1307->regs[DS1307_REG_SECS] & 0x7f);
378 t->tm_min = bcd2bin(ds1307->regs[DS1307_REG_MIN] & 0x7f);
379 tmp = ds1307->regs[DS1307_REG_HOUR] & 0x3f;
380 t->tm_hour = bcd2bin(tmp);
381 t->tm_wday = bcd2bin(ds1307->regs[DS1307_REG_WDAY] & 0x07) - 1;
382 t->tm_mday = bcd2bin(ds1307->regs[DS1307_REG_MDAY] & 0x3f);
383 tmp = ds1307->regs[DS1307_REG_MONTH] & 0x1f;
384 t->tm_mon = bcd2bin(tmp) - 1;
385
386 /* assume 20YY not 19YY, and ignore DS1337_BIT_CENTURY */
387 t->tm_year = bcd2bin(ds1307->regs[DS1307_REG_YEAR]) + 100;
388
389 dev_dbg(dev, "%s secs=%d, mins=%d, "
390 "hours=%d, mday=%d, mon=%d, year=%d, wday=%d\n",
391 "read", t->tm_sec, t->tm_min,
392 t->tm_hour, t->tm_mday,
393 t->tm_mon, t->tm_year, t->tm_wday);
394
395 /* initial clock setting can be undefined */
396 return rtc_valid_tm(t);
397 }
398
399 static int ds1307_set_time(struct device *dev, struct rtc_time *t)
400 {
401 struct ds1307 *ds1307 = dev_get_drvdata(dev);
402 int result;
403 int tmp;
404 u8 *buf = ds1307->regs;
405
406 dev_dbg(dev, "%s secs=%d, mins=%d, "
407 "hours=%d, mday=%d, mon=%d, year=%d, wday=%d\n",
408 "write", t->tm_sec, t->tm_min,
409 t->tm_hour, t->tm_mday,
410 t->tm_mon, t->tm_year, t->tm_wday);
411
412 buf[DS1307_REG_SECS] = bin2bcd(t->tm_sec);
413 buf[DS1307_REG_MIN] = bin2bcd(t->tm_min);
414 buf[DS1307_REG_HOUR] = bin2bcd(t->tm_hour);
415 buf[DS1307_REG_WDAY] = bin2bcd(t->tm_wday + 1);
416 buf[DS1307_REG_MDAY] = bin2bcd(t->tm_mday);
417 buf[DS1307_REG_MONTH] = bin2bcd(t->tm_mon + 1);
418
419 /* assume 20YY not 19YY */
420 tmp = t->tm_year - 100;
421 buf[DS1307_REG_YEAR] = bin2bcd(tmp);
422
423 switch (ds1307->type) {
424 case ds_1337:
425 case ds_1339:
426 case ds_3231:
427 buf[DS1307_REG_MONTH] |= DS1337_BIT_CENTURY;
428 break;
429 case ds_1340:
430 buf[DS1307_REG_HOUR] |= DS1340_BIT_CENTURY_EN
431 | DS1340_BIT_CENTURY;
432 break;
433 case mcp794xx:
434 /*
435 * these bits were cleared when preparing the date/time
436 * values and need to be set again before writing the
437 * buffer out to the device.
438 */
439 buf[DS1307_REG_SECS] |= MCP794XX_BIT_ST;
440 buf[DS1307_REG_WDAY] |= MCP794XX_BIT_VBATEN;
441 break;
442 default:
443 break;
444 }
445
446 dev_dbg(dev, "%s: %7ph\n", "write", buf);
447
448 result = ds1307->write_block_data(ds1307->client,
449 ds1307->offset, 7, buf);
450 if (result < 0) {
451 dev_err(dev, "%s error %d\n", "write", result);
452 return result;
453 }
454 return 0;
455 }
456
457 static int ds1337_read_alarm(struct device *dev, struct rtc_wkalrm *t)
458 {
459 struct i2c_client *client = to_i2c_client(dev);
460 struct ds1307 *ds1307 = i2c_get_clientdata(client);
461 int ret;
462
463 if (!test_bit(HAS_ALARM, &ds1307->flags))
464 return -EINVAL;
465
466 /* read all ALARM1, ALARM2, and status registers at once */
467 ret = ds1307->read_block_data(client,
468 DS1339_REG_ALARM1_SECS, 9, ds1307->regs);
469 if (ret != 9) {
470 dev_err(dev, "%s error %d\n", "alarm read", ret);
471 return -EIO;
472 }
473
474 dev_dbg(dev, "%s: %4ph, %3ph, %2ph\n", "alarm read",
475 &ds1307->regs[0], &ds1307->regs[4], &ds1307->regs[7]);
476
477 /*
478 * report alarm time (ALARM1); assume 24 hour and day-of-month modes,
479 * and that all four fields are checked matches
480 */
481 t->time.tm_sec = bcd2bin(ds1307->regs[0] & 0x7f);
482 t->time.tm_min = bcd2bin(ds1307->regs[1] & 0x7f);
483 t->time.tm_hour = bcd2bin(ds1307->regs[2] & 0x3f);
484 t->time.tm_mday = bcd2bin(ds1307->regs[3] & 0x3f);
485
486 /* ... and status */
487 t->enabled = !!(ds1307->regs[7] & DS1337_BIT_A1IE);
488 t->pending = !!(ds1307->regs[8] & DS1337_BIT_A1I);
489
490 dev_dbg(dev, "%s secs=%d, mins=%d, "
491 "hours=%d, mday=%d, enabled=%d, pending=%d\n",
492 "alarm read", t->time.tm_sec, t->time.tm_min,
493 t->time.tm_hour, t->time.tm_mday,
494 t->enabled, t->pending);
495
496 return 0;
497 }
498
499 static int ds1337_set_alarm(struct device *dev, struct rtc_wkalrm *t)
500 {
501 struct i2c_client *client = to_i2c_client(dev);
502 struct ds1307 *ds1307 = i2c_get_clientdata(client);
503 unsigned char *buf = ds1307->regs;
504 u8 control, status;
505 int ret;
506
507 if (!test_bit(HAS_ALARM, &ds1307->flags))
508 return -EINVAL;
509
510 dev_dbg(dev, "%s secs=%d, mins=%d, "
511 "hours=%d, mday=%d, enabled=%d, pending=%d\n",
512 "alarm set", t->time.tm_sec, t->time.tm_min,
513 t->time.tm_hour, t->time.tm_mday,
514 t->enabled, t->pending);
515
516 /* read current status of both alarms and the chip */
517 ret = ds1307->read_block_data(client,
518 DS1339_REG_ALARM1_SECS, 9, buf);
519 if (ret != 9) {
520 dev_err(dev, "%s error %d\n", "alarm write", ret);
521 return -EIO;
522 }
523 control = ds1307->regs[7];
524 status = ds1307->regs[8];
525
526 dev_dbg(dev, "%s: %4ph, %3ph, %02x %02x\n", "alarm set (old status)",
527 &ds1307->regs[0], &ds1307->regs[4], control, status);
528
529 /* set ALARM1, using 24 hour and day-of-month modes */
530 buf[0] = bin2bcd(t->time.tm_sec);
531 buf[1] = bin2bcd(t->time.tm_min);
532 buf[2] = bin2bcd(t->time.tm_hour);
533 buf[3] = bin2bcd(t->time.tm_mday);
534
535 /* set ALARM2 to non-garbage */
536 buf[4] = 0;
537 buf[5] = 0;
538 buf[6] = 0;
539
540 /* disable alarms */
541 buf[7] = control & ~(DS1337_BIT_A1IE | DS1337_BIT_A2IE);
542 buf[8] = status & ~(DS1337_BIT_A1I | DS1337_BIT_A2I);
543
544 ret = ds1307->write_block_data(client,
545 DS1339_REG_ALARM1_SECS, 9, buf);
546 if (ret < 0) {
547 dev_err(dev, "can't set alarm time\n");
548 return ret;
549 }
550
551 /* optionally enable ALARM1 */
552 if (t->enabled) {
553 dev_dbg(dev, "alarm IRQ armed\n");
554 buf[7] |= DS1337_BIT_A1IE; /* only ALARM1 is used */
555 i2c_smbus_write_byte_data(client, DS1337_REG_CONTROL, buf[7]);
556 }
557
558 return 0;
559 }
560
561 static int ds1307_alarm_irq_enable(struct device *dev, unsigned int enabled)
562 {
563 struct i2c_client *client = to_i2c_client(dev);
564 struct ds1307 *ds1307 = i2c_get_clientdata(client);
565 int ret;
566
567 if (!test_bit(HAS_ALARM, &ds1307->flags))
568 return -ENOTTY;
569
570 ret = i2c_smbus_read_byte_data(client, DS1337_REG_CONTROL);
571 if (ret < 0)
572 return ret;
573
574 if (enabled)
575 ret |= DS1337_BIT_A1IE;
576 else
577 ret &= ~DS1337_BIT_A1IE;
578
579 ret = i2c_smbus_write_byte_data(client, DS1337_REG_CONTROL, ret);
580 if (ret < 0)
581 return ret;
582
583 return 0;
584 }
585
586 static const struct rtc_class_ops ds13xx_rtc_ops = {
587 .read_time = ds1307_get_time,
588 .set_time = ds1307_set_time,
589 .read_alarm = ds1337_read_alarm,
590 .set_alarm = ds1337_set_alarm,
591 .alarm_irq_enable = ds1307_alarm_irq_enable,
592 };
593
594 /*----------------------------------------------------------------------*/
595
596 /*
597 * Alarm support for mcp794xx devices.
598 */
599
600 #define MCP794XX_REG_WEEKDAY 0x3
601 #define MCP794XX_REG_WEEKDAY_WDAY_MASK 0x7
602 #define MCP794XX_REG_CONTROL 0x07
603 # define MCP794XX_BIT_ALM0_EN 0x10
604 # define MCP794XX_BIT_ALM1_EN 0x20
605 #define MCP794XX_REG_ALARM0_BASE 0x0a
606 #define MCP794XX_REG_ALARM0_CTRL 0x0d
607 #define MCP794XX_REG_ALARM1_BASE 0x11
608 #define MCP794XX_REG_ALARM1_CTRL 0x14
609 # define MCP794XX_BIT_ALMX_IF (1 << 3)
610 # define MCP794XX_BIT_ALMX_C0 (1 << 4)
611 # define MCP794XX_BIT_ALMX_C1 (1 << 5)
612 # define MCP794XX_BIT_ALMX_C2 (1 << 6)
613 # define MCP794XX_BIT_ALMX_POL (1 << 7)
614 # define MCP794XX_MSK_ALMX_MATCH (MCP794XX_BIT_ALMX_C0 | \
615 MCP794XX_BIT_ALMX_C1 | \
616 MCP794XX_BIT_ALMX_C2)
617
618 static irqreturn_t mcp794xx_irq(int irq, void *dev_id)
619 {
620 struct i2c_client *client = dev_id;
621 struct ds1307 *ds1307 = i2c_get_clientdata(client);
622 struct mutex *lock = &ds1307->rtc->ops_lock;
623 int reg, ret;
624
625 mutex_lock(lock);
626
627 /* Check and clear alarm 0 interrupt flag. */
628 reg = i2c_smbus_read_byte_data(client, MCP794XX_REG_ALARM0_CTRL);
629 if (reg < 0)
630 goto out;
631 if (!(reg & MCP794XX_BIT_ALMX_IF))
632 goto out;
633 reg &= ~MCP794XX_BIT_ALMX_IF;
634 ret = i2c_smbus_write_byte_data(client, MCP794XX_REG_ALARM0_CTRL, reg);
635 if (ret < 0)
636 goto out;
637
638 /* Disable alarm 0. */
639 reg = i2c_smbus_read_byte_data(client, MCP794XX_REG_CONTROL);
640 if (reg < 0)
641 goto out;
642 reg &= ~MCP794XX_BIT_ALM0_EN;
643 ret = i2c_smbus_write_byte_data(client, MCP794XX_REG_CONTROL, reg);
644 if (ret < 0)
645 goto out;
646
647 rtc_update_irq(ds1307->rtc, 1, RTC_AF | RTC_IRQF);
648
649 out:
650 mutex_unlock(lock);
651
652 return IRQ_HANDLED;
653 }
654
655 static int mcp794xx_read_alarm(struct device *dev, struct rtc_wkalrm *t)
656 {
657 struct i2c_client *client = to_i2c_client(dev);
658 struct ds1307 *ds1307 = i2c_get_clientdata(client);
659 u8 *regs = ds1307->regs;
660 int ret;
661
662 if (!test_bit(HAS_ALARM, &ds1307->flags))
663 return -EINVAL;
664
665 /* Read control and alarm 0 registers. */
666 ret = ds1307->read_block_data(client, MCP794XX_REG_CONTROL, 10, regs);
667 if (ret < 0)
668 return ret;
669
670 t->enabled = !!(regs[0] & MCP794XX_BIT_ALM0_EN);
671
672 /* Report alarm 0 time assuming 24-hour and day-of-month modes. */
673 t->time.tm_sec = bcd2bin(ds1307->regs[3] & 0x7f);
674 t->time.tm_min = bcd2bin(ds1307->regs[4] & 0x7f);
675 t->time.tm_hour = bcd2bin(ds1307->regs[5] & 0x3f);
676 t->time.tm_wday = bcd2bin(ds1307->regs[6] & 0x7) - 1;
677 t->time.tm_mday = bcd2bin(ds1307->regs[7] & 0x3f);
678 t->time.tm_mon = bcd2bin(ds1307->regs[8] & 0x1f) - 1;
679 t->time.tm_year = -1;
680 t->time.tm_yday = -1;
681 t->time.tm_isdst = -1;
682
683 dev_dbg(dev, "%s, sec=%d min=%d hour=%d wday=%d mday=%d mon=%d "
684 "enabled=%d polarity=%d irq=%d match=%d\n", __func__,
685 t->time.tm_sec, t->time.tm_min, t->time.tm_hour,
686 t->time.tm_wday, t->time.tm_mday, t->time.tm_mon, t->enabled,
687 !!(ds1307->regs[6] & MCP794XX_BIT_ALMX_POL),
688 !!(ds1307->regs[6] & MCP794XX_BIT_ALMX_IF),
689 (ds1307->regs[6] & MCP794XX_MSK_ALMX_MATCH) >> 4);
690
691 return 0;
692 }
693
694 static int mcp794xx_set_alarm(struct device *dev, struct rtc_wkalrm *t)
695 {
696 struct i2c_client *client = to_i2c_client(dev);
697 struct ds1307 *ds1307 = i2c_get_clientdata(client);
698 unsigned char *regs = ds1307->regs;
699 int ret;
700
701 if (!test_bit(HAS_ALARM, &ds1307->flags))
702 return -EINVAL;
703
704 dev_dbg(dev, "%s, sec=%d min=%d hour=%d wday=%d mday=%d mon=%d "
705 "enabled=%d pending=%d\n", __func__,
706 t->time.tm_sec, t->time.tm_min, t->time.tm_hour,
707 t->time.tm_wday, t->time.tm_mday, t->time.tm_mon,
708 t->enabled, t->pending);
709
710 /* Read control and alarm 0 registers. */
711 ret = ds1307->read_block_data(client, MCP794XX_REG_CONTROL, 10, regs);
712 if (ret < 0)
713 return ret;
714
715 /* Set alarm 0, using 24-hour and day-of-month modes. */
716 regs[3] = bin2bcd(t->time.tm_sec);
717 regs[4] = bin2bcd(t->time.tm_min);
718 regs[5] = bin2bcd(t->time.tm_hour);
719 regs[6] = bin2bcd(t->time.tm_wday + 1);
720 regs[7] = bin2bcd(t->time.tm_mday);
721 regs[8] = bin2bcd(t->time.tm_mon + 1);
722
723 /* Clear the alarm 0 interrupt flag. */
724 regs[6] &= ~MCP794XX_BIT_ALMX_IF;
725 /* Set alarm match: second, minute, hour, day, date, month. */
726 regs[6] |= MCP794XX_MSK_ALMX_MATCH;
727 /* Disable interrupt. We will not enable until completely programmed */
728 regs[0] &= ~MCP794XX_BIT_ALM0_EN;
729
730 ret = ds1307->write_block_data(client, MCP794XX_REG_CONTROL, 10, regs);
731 if (ret < 0)
732 return ret;
733
734 if (!t->enabled)
735 return 0;
736 regs[0] |= MCP794XX_BIT_ALM0_EN;
737 return i2c_smbus_write_byte_data(client, MCP794XX_REG_CONTROL, regs[0]);
738 }
739
740 static int mcp794xx_alarm_irq_enable(struct device *dev, unsigned int enabled)
741 {
742 struct i2c_client *client = to_i2c_client(dev);
743 struct ds1307 *ds1307 = i2c_get_clientdata(client);
744 int reg;
745
746 if (!test_bit(HAS_ALARM, &ds1307->flags))
747 return -EINVAL;
748
749 reg = i2c_smbus_read_byte_data(client, MCP794XX_REG_CONTROL);
750 if (reg < 0)
751 return reg;
752
753 if (enabled)
754 reg |= MCP794XX_BIT_ALM0_EN;
755 else
756 reg &= ~MCP794XX_BIT_ALM0_EN;
757
758 return i2c_smbus_write_byte_data(client, MCP794XX_REG_CONTROL, reg);
759 }
760
761 static const struct rtc_class_ops mcp794xx_rtc_ops = {
762 .read_time = ds1307_get_time,
763 .set_time = ds1307_set_time,
764 .read_alarm = mcp794xx_read_alarm,
765 .set_alarm = mcp794xx_set_alarm,
766 .alarm_irq_enable = mcp794xx_alarm_irq_enable,
767 };
768
769 /*----------------------------------------------------------------------*/
770
771 static ssize_t
772 ds1307_nvram_read(struct file *filp, struct kobject *kobj,
773 struct bin_attribute *attr,
774 char *buf, loff_t off, size_t count)
775 {
776 struct i2c_client *client;
777 struct ds1307 *ds1307;
778 int result;
779
780 client = kobj_to_i2c_client(kobj);
781 ds1307 = i2c_get_clientdata(client);
782
783 result = ds1307->read_block_data(client, ds1307->nvram_offset + off,
784 count, buf);
785 if (result < 0)
786 dev_err(&client->dev, "%s error %d\n", "nvram read", result);
787 return result;
788 }
789
790 static ssize_t
791 ds1307_nvram_write(struct file *filp, struct kobject *kobj,
792 struct bin_attribute *attr,
793 char *buf, loff_t off, size_t count)
794 {
795 struct i2c_client *client;
796 struct ds1307 *ds1307;
797 int result;
798
799 client = kobj_to_i2c_client(kobj);
800 ds1307 = i2c_get_clientdata(client);
801
802 result = ds1307->write_block_data(client, ds1307->nvram_offset + off,
803 count, buf);
804 if (result < 0) {
805 dev_err(&client->dev, "%s error %d\n", "nvram write", result);
806 return result;
807 }
808 return count;
809 }
810
811
812 /*----------------------------------------------------------------------*/
813
814 static u8 do_trickle_setup_ds1339(struct i2c_client *client,
815 uint32_t ohms, bool diode)
816 {
817 u8 setup = (diode) ? DS1307_TRICKLE_CHARGER_DIODE :
818 DS1307_TRICKLE_CHARGER_NO_DIODE;
819
820 switch (ohms) {
821 case 250:
822 setup |= DS1307_TRICKLE_CHARGER_250_OHM;
823 break;
824 case 2000:
825 setup |= DS1307_TRICKLE_CHARGER_2K_OHM;
826 break;
827 case 4000:
828 setup |= DS1307_TRICKLE_CHARGER_4K_OHM;
829 break;
830 default:
831 dev_warn(&client->dev,
832 "Unsupported ohm value %u in dt\n", ohms);
833 return 0;
834 }
835 return setup;
836 }
837
838 static void ds1307_trickle_of_init(struct i2c_client *client,
839 struct chip_desc *chip)
840 {
841 uint32_t ohms = 0;
842 bool diode = true;
843
844 if (!chip->do_trickle_setup)
845 goto out;
846 if (of_property_read_u32(client->dev.of_node, "trickle-resistor-ohms" , &ohms))
847 goto out;
848 if (of_property_read_bool(client->dev.of_node, "trickle-diode-disable"))
849 diode = false;
850 chip->trickle_charger_setup = chip->do_trickle_setup(client,
851 ohms, diode);
852 out:
853 return;
854 }
855
856 /*----------------------------------------------------------------------*/
857
858 #ifdef CONFIG_RTC_DRV_DS1307_HWMON
859
860 /*
861 * Temperature sensor support for ds3231 devices.
862 */
863
864 #define DS3231_REG_TEMPERATURE 0x11
865
866 /*
867 * A user-initiated temperature conversion is not started by this function,
868 * so the temperature is updated once every 64 seconds.
869 */
870 static int ds3231_hwmon_read_temp(struct device *dev, s32 *mC)
871 {
872 struct ds1307 *ds1307 = dev_get_drvdata(dev);
873 u8 temp_buf[2];
874 s16 temp;
875 int ret;
876
877 ret = ds1307->read_block_data(ds1307->client, DS3231_REG_TEMPERATURE,
878 sizeof(temp_buf), temp_buf);
879 if (ret < 0)
880 return ret;
881 if (ret != sizeof(temp_buf))
882 return -EIO;
883
884 /*
885 * Temperature is represented as a 10-bit code with a resolution of
886 * 0.25 degree celsius and encoded in two's complement format.
887 */
888 temp = (temp_buf[0] << 8) | temp_buf[1];
889 temp >>= 6;
890 *mC = temp * 250;
891
892 return 0;
893 }
894
895 static ssize_t ds3231_hwmon_show_temp(struct device *dev,
896 struct device_attribute *attr, char *buf)
897 {
898 int ret;
899 s32 temp;
900
901 ret = ds3231_hwmon_read_temp(dev, &temp);
902 if (ret)
903 return ret;
904
905 return sprintf(buf, "%d\n", temp);
906 }
907 static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, ds3231_hwmon_show_temp,
908 NULL, 0);
909
910 static struct attribute *ds3231_hwmon_attrs[] = {
911 &sensor_dev_attr_temp1_input.dev_attr.attr,
912 NULL,
913 };
914 ATTRIBUTE_GROUPS(ds3231_hwmon);
915
916 static void ds1307_hwmon_register(struct ds1307 *ds1307)
917 {
918 struct device *dev;
919
920 if (ds1307->type != ds_3231)
921 return;
922
923 dev = devm_hwmon_device_register_with_groups(&ds1307->client->dev,
924 ds1307->client->name,
925 ds1307, ds3231_hwmon_groups);
926 if (IS_ERR(dev)) {
927 dev_warn(&ds1307->client->dev,
928 "unable to register hwmon device %ld\n", PTR_ERR(dev));
929 }
930 }
931
932 #else
933
934 static void ds1307_hwmon_register(struct ds1307 *ds1307)
935 {
936 }
937
938 #endif /* CONFIG_RTC_DRV_DS1307_HWMON */
939
940 /*----------------------------------------------------------------------*/
941
942 /*
943 * Square-wave output support for DS3231
944 * Datasheet: https://datasheets.maximintegrated.com/en/ds/DS3231.pdf
945 */
946 #ifdef CONFIG_COMMON_CLK
947
948 enum {
949 DS3231_CLK_SQW = 0,
950 DS3231_CLK_32KHZ,
951 };
952
953 #define clk_sqw_to_ds1307(clk) \
954 container_of(clk, struct ds1307, clks[DS3231_CLK_SQW])
955 #define clk_32khz_to_ds1307(clk) \
956 container_of(clk, struct ds1307, clks[DS3231_CLK_32KHZ])
957
958 static int ds3231_clk_sqw_rates[] = {
959 1,
960 1024,
961 4096,
962 8192,
963 };
964
965 static int ds1337_write_control(struct ds1307 *ds1307, u8 mask, u8 value)
966 {
967 struct i2c_client *client = ds1307->client;
968 struct mutex *lock = &ds1307->rtc->ops_lock;
969 int control;
970 int ret;
971
972 mutex_lock(lock);
973
974 control = i2c_smbus_read_byte_data(client, DS1337_REG_CONTROL);
975 if (control < 0) {
976 ret = control;
977 goto out;
978 }
979
980 control &= ~mask;
981 control |= value;
982
983 ret = i2c_smbus_write_byte_data(client, DS1337_REG_CONTROL, control);
984 out:
985 mutex_unlock(lock);
986
987 return ret;
988 }
989
990 static unsigned long ds3231_clk_sqw_recalc_rate(struct clk_hw *hw,
991 unsigned long parent_rate)
992 {
993 struct ds1307 *ds1307 = clk_sqw_to_ds1307(hw);
994 int control;
995 int rate_sel = 0;
996
997 control = i2c_smbus_read_byte_data(ds1307->client, DS1337_REG_CONTROL);
998 if (control < 0)
999 return control;
1000 if (control & DS1337_BIT_RS1)
1001 rate_sel += 1;
1002 if (control & DS1337_BIT_RS2)
1003 rate_sel += 2;
1004
1005 return ds3231_clk_sqw_rates[rate_sel];
1006 }
1007
1008 static long ds3231_clk_sqw_round_rate(struct clk_hw *hw, unsigned long rate,
1009 unsigned long *prate)
1010 {
1011 int i;
1012
1013 for (i = ARRAY_SIZE(ds3231_clk_sqw_rates) - 1; i >= 0; i--) {
1014 if (ds3231_clk_sqw_rates[i] <= rate)
1015 return ds3231_clk_sqw_rates[i];
1016 }
1017
1018 return 0;
1019 }
1020
1021 static int ds3231_clk_sqw_set_rate(struct clk_hw *hw, unsigned long rate,
1022 unsigned long parent_rate)
1023 {
1024 struct ds1307 *ds1307 = clk_sqw_to_ds1307(hw);
1025 int control = 0;
1026 int rate_sel;
1027
1028 for (rate_sel = 0; rate_sel < ARRAY_SIZE(ds3231_clk_sqw_rates);
1029 rate_sel++) {
1030 if (ds3231_clk_sqw_rates[rate_sel] == rate)
1031 break;
1032 }
1033
1034 if (rate_sel == ARRAY_SIZE(ds3231_clk_sqw_rates))
1035 return -EINVAL;
1036
1037 if (rate_sel & 1)
1038 control |= DS1337_BIT_RS1;
1039 if (rate_sel & 2)
1040 control |= DS1337_BIT_RS2;
1041
1042 return ds1337_write_control(ds1307, DS1337_BIT_RS1 | DS1337_BIT_RS2,
1043 control);
1044 }
1045
1046 static int ds3231_clk_sqw_prepare(struct clk_hw *hw)
1047 {
1048 struct ds1307 *ds1307 = clk_sqw_to_ds1307(hw);
1049
1050 return ds1337_write_control(ds1307, DS1337_BIT_INTCN, 0);
1051 }
1052
1053 static void ds3231_clk_sqw_unprepare(struct clk_hw *hw)
1054 {
1055 struct ds1307 *ds1307 = clk_sqw_to_ds1307(hw);
1056
1057 ds1337_write_control(ds1307, DS1337_BIT_INTCN, DS1337_BIT_INTCN);
1058 }
1059
1060 static int ds3231_clk_sqw_is_prepared(struct clk_hw *hw)
1061 {
1062 struct ds1307 *ds1307 = clk_sqw_to_ds1307(hw);
1063 int control;
1064
1065 control = i2c_smbus_read_byte_data(ds1307->client, DS1337_REG_CONTROL);
1066 if (control < 0)
1067 return control;
1068
1069 return !(control & DS1337_BIT_INTCN);
1070 }
1071
1072 static const struct clk_ops ds3231_clk_sqw_ops = {
1073 .prepare = ds3231_clk_sqw_prepare,
1074 .unprepare = ds3231_clk_sqw_unprepare,
1075 .is_prepared = ds3231_clk_sqw_is_prepared,
1076 .recalc_rate = ds3231_clk_sqw_recalc_rate,
1077 .round_rate = ds3231_clk_sqw_round_rate,
1078 .set_rate = ds3231_clk_sqw_set_rate,
1079 };
1080
1081 static unsigned long ds3231_clk_32khz_recalc_rate(struct clk_hw *hw,
1082 unsigned long parent_rate)
1083 {
1084 return 32768;
1085 }
1086
1087 static int ds3231_clk_32khz_control(struct ds1307 *ds1307, bool enable)
1088 {
1089 struct i2c_client *client = ds1307->client;
1090 struct mutex *lock = &ds1307->rtc->ops_lock;
1091 int status;
1092 int ret;
1093
1094 mutex_lock(lock);
1095
1096 status = i2c_smbus_read_byte_data(client, DS1337_REG_STATUS);
1097 if (status < 0) {
1098 ret = status;
1099 goto out;
1100 }
1101
1102 if (enable)
1103 status |= DS3231_BIT_EN32KHZ;
1104 else
1105 status &= ~DS3231_BIT_EN32KHZ;
1106
1107 ret = i2c_smbus_write_byte_data(client, DS1337_REG_STATUS, status);
1108 out:
1109 mutex_unlock(lock);
1110
1111 return ret;
1112 }
1113
1114 static int ds3231_clk_32khz_prepare(struct clk_hw *hw)
1115 {
1116 struct ds1307 *ds1307 = clk_32khz_to_ds1307(hw);
1117
1118 return ds3231_clk_32khz_control(ds1307, true);
1119 }
1120
1121 static void ds3231_clk_32khz_unprepare(struct clk_hw *hw)
1122 {
1123 struct ds1307 *ds1307 = clk_32khz_to_ds1307(hw);
1124
1125 ds3231_clk_32khz_control(ds1307, false);
1126 }
1127
1128 static int ds3231_clk_32khz_is_prepared(struct clk_hw *hw)
1129 {
1130 struct ds1307 *ds1307 = clk_32khz_to_ds1307(hw);
1131 int status;
1132
1133 status = i2c_smbus_read_byte_data(ds1307->client, DS1337_REG_STATUS);
1134 if (status < 0)
1135 return status;
1136
1137 return !!(status & DS3231_BIT_EN32KHZ);
1138 }
1139
1140 static const struct clk_ops ds3231_clk_32khz_ops = {
1141 .prepare = ds3231_clk_32khz_prepare,
1142 .unprepare = ds3231_clk_32khz_unprepare,
1143 .is_prepared = ds3231_clk_32khz_is_prepared,
1144 .recalc_rate = ds3231_clk_32khz_recalc_rate,
1145 };
1146
1147 static struct clk_init_data ds3231_clks_init[] = {
1148 [DS3231_CLK_SQW] = {
1149 .name = "ds3231_clk_sqw",
1150 .ops = &ds3231_clk_sqw_ops,
1151 },
1152 [DS3231_CLK_32KHZ] = {
1153 .name = "ds3231_clk_32khz",
1154 .ops = &ds3231_clk_32khz_ops,
1155 },
1156 };
1157
1158 static int ds3231_clks_register(struct ds1307 *ds1307)
1159 {
1160 struct i2c_client *client = ds1307->client;
1161 struct device_node *node = client->dev.of_node;
1162 struct clk_onecell_data *onecell;
1163 int i;
1164
1165 onecell = devm_kzalloc(&client->dev, sizeof(*onecell), GFP_KERNEL);
1166 if (!onecell)
1167 return -ENOMEM;
1168
1169 onecell->clk_num = ARRAY_SIZE(ds3231_clks_init);
1170 onecell->clks = devm_kcalloc(&client->dev, onecell->clk_num,
1171 sizeof(onecell->clks[0]), GFP_KERNEL);
1172 if (!onecell->clks)
1173 return -ENOMEM;
1174
1175 for (i = 0; i < ARRAY_SIZE(ds3231_clks_init); i++) {
1176 struct clk_init_data init = ds3231_clks_init[i];
1177
1178 /*
1179 * Interrupt signal due to alarm conditions and square-wave
1180 * output share same pin, so don't initialize both.
1181 */
1182 if (i == DS3231_CLK_SQW && test_bit(HAS_ALARM, &ds1307->flags))
1183 continue;
1184
1185 /* optional override of the clockname */
1186 of_property_read_string_index(node, "clock-output-names", i,
1187 &init.name);
1188 ds1307->clks[i].init = &init;
1189
1190 onecell->clks[i] = devm_clk_register(&client->dev,
1191 &ds1307->clks[i]);
1192 if (IS_ERR(onecell->clks[i]))
1193 return PTR_ERR(onecell->clks[i]);
1194 }
1195
1196 if (!node)
1197 return 0;
1198
1199 of_clk_add_provider(node, of_clk_src_onecell_get, onecell);
1200
1201 return 0;
1202 }
1203
1204 static void ds1307_clks_register(struct ds1307 *ds1307)
1205 {
1206 int ret;
1207
1208 if (ds1307->type != ds_3231)
1209 return;
1210
1211 ret = ds3231_clks_register(ds1307);
1212 if (ret) {
1213 dev_warn(&ds1307->client->dev,
1214 "unable to register clock device %d\n", ret);
1215 }
1216 }
1217
1218 #else
1219
1220 static void ds1307_clks_register(struct ds1307 *ds1307)
1221 {
1222 }
1223
1224 #endif /* CONFIG_COMMON_CLK */
1225
1226 static int ds1307_probe(struct i2c_client *client,
1227 const struct i2c_device_id *id)
1228 {
1229 struct ds1307 *ds1307;
1230 int err = -ENODEV;
1231 int tmp, wday;
1232 struct chip_desc *chip = &chips[id->driver_data];
1233 struct i2c_adapter *adapter = to_i2c_adapter(client->dev.parent);
1234 bool want_irq = false;
1235 bool ds1307_can_wakeup_device = false;
1236 unsigned char *buf;
1237 struct ds1307_platform_data *pdata = dev_get_platdata(&client->dev);
1238 struct rtc_time tm;
1239 unsigned long timestamp;
1240
1241 irq_handler_t irq_handler = ds1307_irq;
1242
1243 static const int bbsqi_bitpos[] = {
1244 [ds_1337] = 0,
1245 [ds_1339] = DS1339_BIT_BBSQI,
1246 [ds_3231] = DS3231_BIT_BBSQW,
1247 };
1248 const struct rtc_class_ops *rtc_ops = &ds13xx_rtc_ops;
1249
1250 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA)
1251 && !i2c_check_functionality(adapter, I2C_FUNC_SMBUS_I2C_BLOCK))
1252 return -EIO;
1253
1254 ds1307 = devm_kzalloc(&client->dev, sizeof(struct ds1307), GFP_KERNEL);
1255 if (!ds1307)
1256 return -ENOMEM;
1257
1258 i2c_set_clientdata(client, ds1307);
1259
1260 ds1307->client = client;
1261 ds1307->type = id->driver_data;
1262
1263 if (!pdata && client->dev.of_node)
1264 ds1307_trickle_of_init(client, chip);
1265 else if (pdata && pdata->trickle_charger_setup)
1266 chip->trickle_charger_setup = pdata->trickle_charger_setup;
1267
1268 if (chip->trickle_charger_setup && chip->trickle_charger_reg) {
1269 dev_dbg(&client->dev, "writing trickle charger info 0x%x to 0x%x\n",
1270 DS13XX_TRICKLE_CHARGER_MAGIC | chip->trickle_charger_setup,
1271 chip->trickle_charger_reg);
1272 i2c_smbus_write_byte_data(client, chip->trickle_charger_reg,
1273 DS13XX_TRICKLE_CHARGER_MAGIC |
1274 chip->trickle_charger_setup);
1275 }
1276
1277 buf = ds1307->regs;
1278 if (i2c_check_functionality(adapter, I2C_FUNC_SMBUS_I2C_BLOCK)) {
1279 ds1307->read_block_data = ds1307_native_smbus_read_block_data;
1280 ds1307->write_block_data = ds1307_native_smbus_write_block_data;
1281 } else {
1282 ds1307->read_block_data = ds1307_read_block_data;
1283 ds1307->write_block_data = ds1307_write_block_data;
1284 }
1285
1286 #ifdef CONFIG_OF
1287 /*
1288 * For devices with no IRQ directly connected to the SoC, the RTC chip
1289 * can be forced as a wakeup source by stating that explicitly in
1290 * the device's .dts file using the "wakeup-source" boolean property.
1291 * If the "wakeup-source" property is set, don't request an IRQ.
1292 * This will guarantee the 'wakealarm' sysfs entry is available on the device,
1293 * if supported by the RTC.
1294 */
1295 if (of_property_read_bool(client->dev.of_node, "wakeup-source")) {
1296 ds1307_can_wakeup_device = true;
1297 }
1298 #endif
1299
1300 switch (ds1307->type) {
1301 case ds_1337:
1302 case ds_1339:
1303 case ds_3231:
1304 /* get registers that the "rtc" read below won't read... */
1305 tmp = ds1307->read_block_data(ds1307->client,
1306 DS1337_REG_CONTROL, 2, buf);
1307 if (tmp != 2) {
1308 dev_dbg(&client->dev, "read error %d\n", tmp);
1309 err = -EIO;
1310 goto exit;
1311 }
1312
1313 /* oscillator off? turn it on, so clock can tick. */
1314 if (ds1307->regs[0] & DS1337_BIT_nEOSC)
1315 ds1307->regs[0] &= ~DS1337_BIT_nEOSC;
1316
1317 /*
1318 * Using IRQ or defined as wakeup-source?
1319 * Disable the square wave and both alarms.
1320 * For some variants, be sure alarms can trigger when we're
1321 * running on Vbackup (BBSQI/BBSQW)
1322 */
1323 if (chip->alarm && (ds1307->client->irq > 0 ||
1324 ds1307_can_wakeup_device)) {
1325 ds1307->regs[0] |= DS1337_BIT_INTCN
1326 | bbsqi_bitpos[ds1307->type];
1327 ds1307->regs[0] &= ~(DS1337_BIT_A2IE | DS1337_BIT_A1IE);
1328
1329 want_irq = true;
1330 }
1331
1332 i2c_smbus_write_byte_data(client, DS1337_REG_CONTROL,
1333 ds1307->regs[0]);
1334
1335 /* oscillator fault? clear flag, and warn */
1336 if (ds1307->regs[1] & DS1337_BIT_OSF) {
1337 i2c_smbus_write_byte_data(client, DS1337_REG_STATUS,
1338 ds1307->regs[1] & ~DS1337_BIT_OSF);
1339 dev_warn(&client->dev, "SET TIME!\n");
1340 }
1341 break;
1342
1343 case rx_8025:
1344 tmp = i2c_smbus_read_i2c_block_data(ds1307->client,
1345 RX8025_REG_CTRL1 << 4 | 0x08, 2, buf);
1346 if (tmp != 2) {
1347 dev_dbg(&client->dev, "read error %d\n", tmp);
1348 err = -EIO;
1349 goto exit;
1350 }
1351
1352 /* oscillator off? turn it on, so clock can tick. */
1353 if (!(ds1307->regs[1] & RX8025_BIT_XST)) {
1354 ds1307->regs[1] |= RX8025_BIT_XST;
1355 i2c_smbus_write_byte_data(client,
1356 RX8025_REG_CTRL2 << 4 | 0x08,
1357 ds1307->regs[1]);
1358 dev_warn(&client->dev,
1359 "oscillator stop detected - SET TIME!\n");
1360 }
1361
1362 if (ds1307->regs[1] & RX8025_BIT_PON) {
1363 ds1307->regs[1] &= ~RX8025_BIT_PON;
1364 i2c_smbus_write_byte_data(client,
1365 RX8025_REG_CTRL2 << 4 | 0x08,
1366 ds1307->regs[1]);
1367 dev_warn(&client->dev, "power-on detected\n");
1368 }
1369
1370 if (ds1307->regs[1] & RX8025_BIT_VDET) {
1371 ds1307->regs[1] &= ~RX8025_BIT_VDET;
1372 i2c_smbus_write_byte_data(client,
1373 RX8025_REG_CTRL2 << 4 | 0x08,
1374 ds1307->regs[1]);
1375 dev_warn(&client->dev, "voltage drop detected\n");
1376 }
1377
1378 /* make sure we are running in 24hour mode */
1379 if (!(ds1307->regs[0] & RX8025_BIT_2412)) {
1380 u8 hour;
1381
1382 /* switch to 24 hour mode */
1383 i2c_smbus_write_byte_data(client,
1384 RX8025_REG_CTRL1 << 4 | 0x08,
1385 ds1307->regs[0] |
1386 RX8025_BIT_2412);
1387
1388 tmp = i2c_smbus_read_i2c_block_data(ds1307->client,
1389 RX8025_REG_CTRL1 << 4 | 0x08, 2, buf);
1390 if (tmp != 2) {
1391 dev_dbg(&client->dev, "read error %d\n", tmp);
1392 err = -EIO;
1393 goto exit;
1394 }
1395
1396 /* correct hour */
1397 hour = bcd2bin(ds1307->regs[DS1307_REG_HOUR]);
1398 if (hour == 12)
1399 hour = 0;
1400 if (ds1307->regs[DS1307_REG_HOUR] & DS1307_BIT_PM)
1401 hour += 12;
1402
1403 i2c_smbus_write_byte_data(client,
1404 DS1307_REG_HOUR << 4 | 0x08,
1405 hour);
1406 }
1407 break;
1408 case ds_1388:
1409 ds1307->offset = 1; /* Seconds starts at 1 */
1410 break;
1411 case mcp794xx:
1412 rtc_ops = &mcp794xx_rtc_ops;
1413 if (ds1307->client->irq > 0 && chip->alarm) {
1414 irq_handler = mcp794xx_irq;
1415 want_irq = true;
1416 }
1417 break;
1418 default:
1419 break;
1420 }
1421
1422 read_rtc:
1423 /* read RTC registers */
1424 tmp = ds1307->read_block_data(ds1307->client, ds1307->offset, 8, buf);
1425 if (tmp != 8) {
1426 dev_dbg(&client->dev, "read error %d\n", tmp);
1427 err = -EIO;
1428 goto exit;
1429 }
1430
1431 /*
1432 * minimal sanity checking; some chips (like DS1340) don't
1433 * specify the extra bits as must-be-zero, but there are
1434 * still a few values that are clearly out-of-range.
1435 */
1436 tmp = ds1307->regs[DS1307_REG_SECS];
1437 switch (ds1307->type) {
1438 case ds_1307:
1439 case m41t00:
1440 /* clock halted? turn it on, so clock can tick. */
1441 if (tmp & DS1307_BIT_CH) {
1442 i2c_smbus_write_byte_data(client, DS1307_REG_SECS, 0);
1443 dev_warn(&client->dev, "SET TIME!\n");
1444 goto read_rtc;
1445 }
1446 break;
1447 case ds_1338:
1448 /* clock halted? turn it on, so clock can tick. */
1449 if (tmp & DS1307_BIT_CH)
1450 i2c_smbus_write_byte_data(client, DS1307_REG_SECS, 0);
1451
1452 /* oscillator fault? clear flag, and warn */
1453 if (ds1307->regs[DS1307_REG_CONTROL] & DS1338_BIT_OSF) {
1454 i2c_smbus_write_byte_data(client, DS1307_REG_CONTROL,
1455 ds1307->regs[DS1307_REG_CONTROL]
1456 & ~DS1338_BIT_OSF);
1457 dev_warn(&client->dev, "SET TIME!\n");
1458 goto read_rtc;
1459 }
1460 break;
1461 case ds_1340:
1462 /* clock halted? turn it on, so clock can tick. */
1463 if (tmp & DS1340_BIT_nEOSC)
1464 i2c_smbus_write_byte_data(client, DS1307_REG_SECS, 0);
1465
1466 tmp = i2c_smbus_read_byte_data(client, DS1340_REG_FLAG);
1467 if (tmp < 0) {
1468 dev_dbg(&client->dev, "read error %d\n", tmp);
1469 err = -EIO;
1470 goto exit;
1471 }
1472
1473 /* oscillator fault? clear flag, and warn */
1474 if (tmp & DS1340_BIT_OSF) {
1475 i2c_smbus_write_byte_data(client, DS1340_REG_FLAG, 0);
1476 dev_warn(&client->dev, "SET TIME!\n");
1477 }
1478 break;
1479 case mcp794xx:
1480 /* make sure that the backup battery is enabled */
1481 if (!(ds1307->regs[DS1307_REG_WDAY] & MCP794XX_BIT_VBATEN)) {
1482 i2c_smbus_write_byte_data(client, DS1307_REG_WDAY,
1483 ds1307->regs[DS1307_REG_WDAY]
1484 | MCP794XX_BIT_VBATEN);
1485 }
1486
1487 /* clock halted? turn it on, so clock can tick. */
1488 if (!(tmp & MCP794XX_BIT_ST)) {
1489 i2c_smbus_write_byte_data(client, DS1307_REG_SECS,
1490 MCP794XX_BIT_ST);
1491 dev_warn(&client->dev, "SET TIME!\n");
1492 goto read_rtc;
1493 }
1494
1495 break;
1496 default:
1497 break;
1498 }
1499
1500 tmp = ds1307->regs[DS1307_REG_HOUR];
1501 switch (ds1307->type) {
1502 case ds_1340:
1503 case m41t00:
1504 /*
1505 * NOTE: ignores century bits; fix before deploying
1506 * systems that will run through year 2100.
1507 */
1508 break;
1509 case rx_8025:
1510 break;
1511 default:
1512 if (!(tmp & DS1307_BIT_12HR))
1513 break;
1514
1515 /*
1516 * Be sure we're in 24 hour mode. Multi-master systems
1517 * take note...
1518 */
1519 tmp = bcd2bin(tmp & 0x1f);
1520 if (tmp == 12)
1521 tmp = 0;
1522 if (ds1307->regs[DS1307_REG_HOUR] & DS1307_BIT_PM)
1523 tmp += 12;
1524 i2c_smbus_write_byte_data(client,
1525 ds1307->offset + DS1307_REG_HOUR,
1526 bin2bcd(tmp));
1527 }
1528
1529 /*
1530 * Some IPs have weekday reset value = 0x1 which might not correct
1531 * hence compute the wday using the current date/month/year values
1532 */
1533 ds1307_get_time(&client->dev, &tm);
1534 wday = tm.tm_wday;
1535 timestamp = rtc_tm_to_time64(&tm);
1536 rtc_time64_to_tm(timestamp, &tm);
1537
1538 /*
1539 * Check if reset wday is different from the computed wday
1540 * If different then set the wday which we computed using
1541 * timestamp
1542 */
1543 if (wday != tm.tm_wday) {
1544 wday = i2c_smbus_read_byte_data(client, MCP794XX_REG_WEEKDAY);
1545 wday = wday & ~MCP794XX_REG_WEEKDAY_WDAY_MASK;
1546 wday = wday | (tm.tm_wday + 1);
1547 i2c_smbus_write_byte_data(client, MCP794XX_REG_WEEKDAY, wday);
1548 }
1549
1550 if (want_irq) {
1551 device_set_wakeup_capable(&client->dev, true);
1552 set_bit(HAS_ALARM, &ds1307->flags);
1553 }
1554 ds1307->rtc = devm_rtc_device_register(&client->dev, client->name,
1555 rtc_ops, THIS_MODULE);
1556 if (IS_ERR(ds1307->rtc)) {
1557 return PTR_ERR(ds1307->rtc);
1558 }
1559
1560 if (ds1307_can_wakeup_device && ds1307->client->irq <= 0) {
1561 /* Disable request for an IRQ */
1562 want_irq = false;
1563 dev_info(&client->dev, "'wakeup-source' is set, request for an IRQ is disabled!\n");
1564 /* We cannot support UIE mode if we do not have an IRQ line */
1565 ds1307->rtc->uie_unsupported = 1;
1566 }
1567
1568 if (want_irq) {
1569 err = devm_request_threaded_irq(&client->dev,
1570 client->irq, NULL, irq_handler,
1571 IRQF_SHARED | IRQF_ONESHOT,
1572 ds1307->rtc->name, client);
1573 if (err) {
1574 client->irq = 0;
1575 device_set_wakeup_capable(&client->dev, false);
1576 clear_bit(HAS_ALARM, &ds1307->flags);
1577 dev_err(&client->dev, "unable to request IRQ!\n");
1578 } else
1579 dev_dbg(&client->dev, "got IRQ %d\n", client->irq);
1580 }
1581
1582 if (chip->nvram_size) {
1583
1584 ds1307->nvram = devm_kzalloc(&client->dev,
1585 sizeof(struct bin_attribute),
1586 GFP_KERNEL);
1587 if (!ds1307->nvram) {
1588 dev_err(&client->dev, "cannot allocate memory for nvram sysfs\n");
1589 } else {
1590
1591 ds1307->nvram->attr.name = "nvram";
1592 ds1307->nvram->attr.mode = S_IRUGO | S_IWUSR;
1593
1594 sysfs_bin_attr_init(ds1307->nvram);
1595
1596 ds1307->nvram->read = ds1307_nvram_read;
1597 ds1307->nvram->write = ds1307_nvram_write;
1598 ds1307->nvram->size = chip->nvram_size;
1599 ds1307->nvram_offset = chip->nvram_offset;
1600
1601 err = sysfs_create_bin_file(&client->dev.kobj,
1602 ds1307->nvram);
1603 if (err) {
1604 dev_err(&client->dev,
1605 "unable to create sysfs file: %s\n",
1606 ds1307->nvram->attr.name);
1607 } else {
1608 set_bit(HAS_NVRAM, &ds1307->flags);
1609 dev_info(&client->dev, "%zu bytes nvram\n",
1610 ds1307->nvram->size);
1611 }
1612 }
1613 }
1614
1615 ds1307_hwmon_register(ds1307);
1616 ds1307_clks_register(ds1307);
1617
1618 return 0;
1619
1620 exit:
1621 return err;
1622 }
1623
1624 static int ds1307_remove(struct i2c_client *client)
1625 {
1626 struct ds1307 *ds1307 = i2c_get_clientdata(client);
1627
1628 if (test_and_clear_bit(HAS_NVRAM, &ds1307->flags))
1629 sysfs_remove_bin_file(&client->dev.kobj, ds1307->nvram);
1630
1631 return 0;
1632 }
1633
1634 static struct i2c_driver ds1307_driver = {
1635 .driver = {
1636 .name = "rtc-ds1307",
1637 },
1638 .probe = ds1307_probe,
1639 .remove = ds1307_remove,
1640 .id_table = ds1307_id,
1641 };
1642
1643 module_i2c_driver(ds1307_driver);
1644
1645 MODULE_DESCRIPTION("RTC driver for DS1307 and similar chips");
1646 MODULE_LICENSE("GPL");
Linux kernel - Deliverables
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